Mammalian Cell Expression System

Introduction:

The prokaryotic expression system has the advantages of high expression level, simple operation, short cycle, easy large-scale and high-density culture and low cost. For the full-length antibody and glycoprotein biological drug, the folding of expression product polypeptide chain, the disulfide bond, the presence or absence of glycosylation and the type of glycosylation often affect the properties of the synthesis, secretion, biological activity, in vivo stability, and immunogenicity of the expressed product. Compared with other eukaryotic expression systems, the expression of the target gene in mammalian cells is similar to that of the native protein in the type and manner of the glycosylation, and can be correctly assembled into the multi-subunit protein.

Advantages:

No self-produced endotoxin

Secretion expression is available

With a variety of complex N-linked glycosylation, accurate O-linked glycosylation and other post-translational processing

Close to native protein in the molecular structure, physical and chemical properties and biological functions

Multiple vectors optimization, More options for customersIn order to improve the success rate of expression and achieve higher yield, in addition to conventional N-terminal fusion protein expression, we also provide C-terminal fusion protein, which retains the bioactivity of the protein while ensuring high purity.

15-20 business days

The PCR amplification products are ligated to the vectors e.g. pSec series, pCMV series and pcDNA series vectors

Transform TOP10 E.coil competent cells

Obtain the correct recombinant plasmid

2

Small scale expression

Prepare the transfection grade recombinant plasmid in large quantities

Optimization of transfection conditionsSet different transfection conditions, select the optimal experimental conditions according to the test results.

9-11 business days

Transient transfect HEK293, CHO and other cells

Detect expression products

3

Scale up expression and purification

Scale up the culture cells and transfect

Multi-condition expression scheme According to the protein localization and the best experimental conditions in the small test expression, select different cell lines and different ways of transfection, which can increase the expression quantity, greatly improve the protein expression.

8-9 business days

Explore different chromatographic conditions including ion exchange, hydrophobic and others by using AKTA, and then determine the optimal purification method.

4

Additional services (Optional)

Charge

Tag removal by restriction digestion

Flexible additional services Customers can flexibly choose from a variety of additional services to their specific needs, e.g. Endotoxin removal, Filter-sterilization, Tag removal, Lyophilization, etc. Some are complimentary, and some require additional charge.

3 business days

Free

Filter-sterilization; Endotoxin removal; Lyophilization (Note: Lyophilization and Filter-sterilization can not be met simultaneously)

2 business days

5

Quality Control

Testing of purity, concentration, etc. QC report is provided.

Detailed COA reportDetailed product data sheet and COA are provided for each project.

Case 1It is well known that the expression yield of mammalian cells is relatively low, the protein was optimally expressed with our mammalian expression system, the target band can be observed by SDS-PAGE analysis of the culture supernatants. The purified protein expression level can up to 10 mg/L. The theoretical molecular weight of the protein was 42 kDa, and the protein is modified with glycosylation by SDS-PAGE, which was confirmed by the examination of LC-MS/MS.

Lane 1：Flow through

Lane 2：Culture medium stoste

Lane 3：Marker

Lane 4：20 mM imidazole elution

Lane 5：60 mM imidazole elution

Case 2Three full-length antibodies were transfected into CHO cells using our vector, after SDS-PAGE detection, the bands were observed in the supernatant of the culture medium, the expressed level was up to 100 mg/L.